The present invention relates to new phenylalanine derivatives and the use of the phenylalanine derivatives as medicines. It was reported that a 4xcex27 integrin-depending adhesion process participates the pathology, such as inflammatory bowel diseases, diabetes, tumor proliferation and tumor metastasis. The compounds of the present invention having an antagonistic effect on the xcex14xcex27 integrins are usable as therapeutic agents or preventive agents for the above-described diseases.
It is generally understood that when a microorganism invades a living tissue or when the tissue is injured, inflammatory reactions play an important role for the exclusion of the microorganism or for the reparation of the injured tissue. As the technique of cytobiological analysis in inflammatory reactions developed, it has been elucidated that an excess progress of the inflammatory reactions plays an important role in causing various diseases including chronic diseases. Namely, by analyzing the inflammatory reactions in each disease, a method for controlling the inflammation in each disease is found and thus, it becomes possible to develop a new therapeutic method. For causing the inflammatory reactions, leukocytes usually circulating in the blood must pass through the vascular wall and be newly supplied to the injured tissue. The infiltration of the leukocytes from the blood vessel into the tissue is carried out by a series of different reactions subsequently occurred. Various cytokines released from the inflamed tissue activate the vascular-endothelium cells in the inflamed tissue and induce the expression of numerous cell surface antigens participating in the adhesion to leukocytes. They include, for example, E-selectin participating in the adhesion of neutrophils; ICAM-1 (Intercellular adhesion molecule-1) which participates in the interaction with LFA-1 (Leukocyte function-associated antigen-1) on the leukocytes; and VCAM-1 (Vascular cell adhesion molecule-1) which participates in the adhesion to xcex14xcex21 integrin (VLA-4 (Very late antigen-4)) on the leukocytes. When the leukocytes in the blood flow reach the activated vascular-endothelium, the leukocytes cause a phenomenon called xe2x80x9crollingxe2x80x9d in which the leukocytes slowly roll on the vascular-endothelium cells. It was made evident that the rolling phenomenon occurs due to the interaction between selectin (particularly L-selectin) on the leukocytes and a particular sugar chain structure on the vascular-endothelium cells. It is generally said that for the extravascular infiltration of leukocytes, a strong adhesion by the interaction between integrin molecules which are a series of hetero-dimer protein on the leukocytes and the above-described cell-adhesion molecules on the vascular-endothelium such as ICAM-1 and VCAM-1 is necessitated after the weak interaction between the leukocytes and the vascular-endothelium cells due to the rolling phenomenon. Usually, integrin molecules expressing on the leukocytes have only a weak binding affinity for cell adhesion molecules expressing on the vascular-endothelium and, therefore, the adhesion is not strong. On the other hand, in an inflamed tissue, the leukocytes are activated by chemokine on the vascular-endothelium in the course of the rolling phenomenon of the leukocytes to reinforce the binding affinity with the integrin on the cell surfaces and thereby to make the strong adhesion and extravascular infiltration possible.
The leukocytes which infiltrate into an inflammatory site are mainly polymorphonuclear leukocytes in acute inflammations, but they are mainly lymphocytes or macrophages in chronic inflammations. Many kinds of lymphocytes do not return into a blood vessel after they once infiltrate into an extravascular tissue by an inflammatory stimulation. On the other hand, lymphocytes mainly comprising T cells and B cells participate in the control of immunologic reactions because they reciprocate between the extravascular tissue and the blood by so-called lymphocyte homing phenomenon in which they move from the blood into the lymphoid tissue through the vessel wall and then return into the blood through the lymph vessel even under physiological conditions. During the lymphocytes repeat the homing phenomenon, they meet an exogenous antigen in a peripheral tissue or a secondary lymphoid tissue and they are sensitized to the antigen. Thus, they differentiate from native cells into memory/effector cells. The lymphocytes thus differentiated into the memory/effector cells are divided into specified subsets and move into specified peripheral tissues such as the skin, lungs and mucosal tissue to control tissue-specific immunologic reactions and inflammatory reactions. Recently, a group of molecules having an important role for determining the tissue-specific homing reaction was elucidated. Namely, they are a homing receptor expressing on the lymphocytes and addressin expressing on the vascular-endothelium. It was elucidated that L-selectin on leukocytes and GlyCAM-1 (Glycosylation-dependent cell adhesion molecule-1) and CD34 on the vascular-endothelium act as the homing receptor and addressin, respectively, in the homing to the peripheral lymph node; that CLA (cutaneous lymphocyte antigen) and E-selectin similarly act in the homing to the skin; and that xcex14xcex27 integrin and MAdCAM-1 (mucosal addressin cell adhesion molecule-1) similarly act in the homing to the intestinal mucosa. In fact, Picker et al. proved that lymphocytes separated from the skin, pneumonic tissue and appendix highly express the respective homing receptors by using the actual tissues of patients (Picker et at., J. Immunol. 150:1122-1136, 1993 and Picker et al., Eur. J. Immunol. 24: 1269-1277, 1994). In the control of an inflammation reaction in a specified tissue, the inhibition of the adhesion mechanism concerning those tissue-specific homing is capable of realizing a more excellent selectivity toward the inhibition of the adhesion mechanism widely realized in the inflammation reaction. Thus, the above-described facts indicate the possibility of being the targets of an ideal medicine having only slight side reaction.
Inflammatory bowel diseases typified by ulcerative colitis and Crohn""s disease are intractable inflammatory diseases because they gradually become chronic after the repetition of recurrence and remission. Although the cause of these diseases have not been elucidated, it is considered that an immunologic abnormality in the intestinal tissue strongly relates to the disease. It was also elucidated that an abnormality of the adhesion mechanism concerning the intestinal tissue-specific homing relates to these diseases. Briskin et al reported an increase in the expression of MAdCAM-1 in a location of intestinal inflammation in patients of inflammatory intestinal diseases such as Crohn""s disease and ulcerative colitis (Briskin et al., Am. J. Pathol. 151: 97-110, 1997). Connor et al. recognized an increase in the expression of MAdCAM-1 i n a location of intestinal inflammation of each interleukin 10 knockout mouse which was one of the well recognized models of inflammatory bowel diseases (Connor et al., J. Leukoc. Biol. 65: 349-355, 1999). Further, in view of the fact that the conditions of mouse models suffering from inflammatory bowel diseases are improved by the administration of anti MAd CAM antibody or anti xcex27 integrin antibody in vivo, it is apparent that the acceleration of the adhesion mechanism of xcex14xcex27 integrin and MAdCAM-1 relates to the development of the diseases (Picarella et al., J. Immunol., 158: 2099-2106, 1997). Recently, it was elucidated that the acceleration of the mucosal tissue-specific homing mechanism concerns the development of insulin-dependent diabetes. Namely, Hanninen et al. reported that induction of the expression of MAdCAM-1 is observed in an inflamed tissue of Langerhans island of NOD mice which are models of an insulin-dependent diabetes (Hanninen et al., J. Immunol. 160: 6018-6025, 1998). Yang et al. reported that the disease of NOD mouse models is improved by the administration of anti xcex27 antibody (Yang et al., Diabetes 46: 1542-1547, 1997). It was also reported that in certain leukemia, the adhesion of xcex27 integrin to MAdCAM-1 is important for the metastatic infiltration into the mucosal tissues of digestive tracts (Chen et al., J. Clin. Immunol. 19: 186-193, 1999).
xcex14xcex27 integrin concerning the intestinal tissue-specific homing mechanism belongs to a 4 subfamily. As the integrins belonging to xcex14 subfamily, VLA-4 (very late antigen-4) molecules comprising xcex14xcex21 chain are known in addition to xcex14xcex27 integrin. The expression of VCAM-1 as the ligand of VLA-4 in the vascular-endothelium cells is induced systemically by substances causing the inflammation such as LPS (Lipopolysaccharide), TNF-xcex1 (Tumor necrosis factor-xcex1) and IL-1. In the course of the inflammation, the infiltration of leukocytes from the blood flow into the inflammatory tissue is conducted by the VLA-4/VCAM-1 adhesion mechanism (Elices, Cell 60: 577-584, 1990, Osborn et al., Cell 59:1203-1211, 1989, Issekutz et al., J. Eex. Med. 183: 2175-2184, 1996). The participation of the adhesion mechanism of xcex14xcex21/VCAM-1 in various pathological stages was reported with reference to the patients with autoimmune diseases such as rheumatoid synovial membrane (van Dinther-Janssen, J. Immunol. 147: 4207-4210, 1991 and Morales-Ducret et al., J. Immunol. 149: 1424-1431, 1992), lungs and respiratory tract epithelium in asthma (ten Hacken et al., Clin. Exp. Allergy 12: 1518-1525, 1998) and allergic diseases (Randolph et al., J. Clin. Invest. 104: 1021-1029, 1999), systemic erythematodes (Takeuchi et al., J. Clin. Invest. 92: 3008-3016, 1993), Sjogren""s syndrome (Edwards et al., Ann. Rheum. Dis. 52: 806-811, 1993), multiple sclerosis (Steffen et al., Am. J. Pathol. 145: 189-201, 1994) and psoriasis (Groves et al., J. Am. Acad. Dermatol. 29: 67-72, 1993). Also in the infiltration of virus-disturbing CD8 positive T cells into a virus-sensitized location, the xcex14xcex21/VCAM adhesion mechanism is employed (Christensen et al., J. Immunol. 154: 5293-5301, 1995). The above-described facts prove that the xcex14xcex21/VCAM-1 adhesion mechanism participates in not only the inflammation stage in the mucosal tissue but also the systemic, general inflammation reactions.
Further, it was elucidated that the binding specificity of xcex14xcex21 integrin is similar to that of xcex14xcex27 integrin because of the similarity in the structure of them. Only xcex14xcex27 integrin has the binding specificity to the above-described MAdCAM-1. On the other hand, VCAM-1 and fibronectin which are other ligands known to be capable of binding to xcex14xcex27 integrin are also capable of binding to xcex14xcex21 integrin. Many of integrins using extracellular matrixes as the ligands, such as VLA-5xcex2-3 subfamily and xcex2-5 subfamily, recognize arginine-glycine-aspartic acid (RGD) sequence in fibronectin, vitronectin, tenascin and osteopontin. On the other hand, in the interaction of xcex14xcex21 and xcex14xcex27 with fibronectin, the RGD sequence does not participate but a CS1 peptide part comprising leucinie-aspartic acid-valine (LDV) as the core sequence participates. Clements et al. found a sequence similar to LDV in amino acid sequences of VCAM-1 and MAdCAM-1. It was elucidated that a variant obtained by partially modifying the CS-1-like sequence of VCAM-1 and MAdCAM-1 molecules cannot interact with xcex14xcex21 integrin and xcex14xcex27 integrin (Clements et al., Vonderheide et al., Renz et al.). Thus, it was found that the CS-1-like sequence is important for the interaction of xcex14xcex21/xcex14xcex27 with VCAM-1/MAdCAM-1. It was reported that the same cyclic peptide having the CS-1-like structure is antagonistic to the interaction of xcex14xcex21 and xcex14xcex27 with VCAM-1, MAdCAM-1 or CS-1 peptide (Vanderslice et al., JI 158: 1710, 1997). The above-described facts indicate that the selective control of the binding specificity of xcex14xcex27 and xcex14xcex21 is difficult.
As described above, the adhesion mechanism of xcex14xcex27 and VCAM-1 widely concerns the inflammation reaction in the whole body including the inflammation process in mucosal tissues. A suitable xcex14 integrin antagonist capable of inhibiting the adhesion of both xcex14xcex21 and xcex14xcex27 is usable as a therapeutic agent for these ordinary inflammatory diseases. However, taking the control of chronic inflammations in intestinal mucosal tissue in a case of, for example, an inflammatory bowel disease into consideration, it is undesirable to inhibit the adhesion of both xcex14xcex21 and xcex14xcex27 for a long time because a risk of the systemic infection or the like is increased, while the inflammation reaction in the intestinal tissue can be inhibited. Also from the viewpoint of the safety, it is desirable to control only the xcex14xcex27 adhesion pathway which is more specific to the inflammation of intestinal mucosa.
Thus, the finding of a suitable antagonist which is inert to xcex14xcex21 but specifically reactive on xcex14xcex27 makes it possible to use the antagonist as a therapeutic agent for the above-described inflammatory bowel diseases and diabetes and also for controlling metastasis of some kinds of leukemia. The use of peptide compounds and amino acid derivatives as the antagonists to xcex14 integrin is described in WO 94/15958, WO 95/15973, WO 96/00581, WO 96/06108, WO 99/10313, WO 99/36393, etc. However, those antagonists have only an insufficient selectivity toward xcex14xcex27 and they are unsuitable for use as antagonists specific to xcex14xcex27. Thus, there is no antagonist specific to xcex14xcex27 and practically usable for the therapeutic purpose at present.
An object of the present invention is to provide new compounds antagonistic to xcex14xcex27 integrin.
Another object of the present invention is to provide an antagonist to xcex14xcex27 integrin.
A still another object of the present invention is to provide a therapeutic agent or preventive agent for diseases in which xcex14xcex27 integrin-depending adhesion process participates in the pathology, such as inflammatory bowel diseases, diabetes, tumor proliferation and tumor metastasis.
A further object of the present invention is to provide a pharmaceutical composition containing such a new compound.
After synthesizing various phenylalanine derivatives and examining xcex14 integrin antagonistic activities thereof for the purpose of solving the above-described problems, the inventors have found that specified, new phenylalanine derivatives, particularly compounds of the following general formula (1), have excellent antagonistic activity to xcex14xcex27 integrin and selectivity to other integrins such as xcex14xcex21 integrin. The present invention has been completed on the basis of this finding.
Namely, the present invention provides phenylalanine derivatives of the following general formula (1) and pharmaceutically acceptable salts thereof: 
wherein X represents an interatomic bond, xe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94SO2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94C(xe2x95x90O)xe2x80x94, xe2x80x94NR1xe2x80x94SO2xe2x80x94, xe2x80x94NR1xe2x80x94C(xe2x95x90O)xe2x80x94NHxe2x80x94, xe2x80x94NR1xe2x80x94C(xe2x95x90S)xe2x80x94NHxe2x80x94 or xe2x80x94C(xe2x95x90O)xe2x80x94, wherein R1 represents a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkenyl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group or a lower alkyl group substituted with a heteroaryl group;
Y represents N or CH;
Z represents xe2x80x94C(xe2x95x90O)xe2x80x94, xe2x80x94S(xe2x95x90O)xe2x80x94 or xe2x80x94SO2xe2x80x94;
A represents a group of the following general formula (2), a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with a group of general formula (2), a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkenyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkenyl group substituted with an aryl group, a lower alkenyl group substituted with a heteroaryl group, a lower alkynyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkynyl group substituted with an aryl group or a lower alkynyl group substituted with a heteroaryl group: 
wherein R2, R3, R4, R5 and R6 may be the same or different from one another, and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkoxyl group, a lower alkoxyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkoxyl group substituted with an aryl group, a lower alkoxyl group substituted with a heteroaryl group, a cycloalkyloxy group which may contain a hetero atom(s) in the ring thereof, an aryloxy group, a heteroaryloxy group, a hydroxy-lower alkyl group, a hydroxy-lower alkenyl group, a hydroxy-lower alkoxyl group, a halogeno-lower alkyl group, a halogeno-lower alkoxyl group, a halogeno-lower alkenyl group, a nitro group, a cyano group, a substituted or unsubstituted amino group, a carboxyl group, a lower alkyloxycarbonyl group, a substituted or unsubstituted carbamoyl group, a lower alkanoyl group, an aroyl group, a lower alkylthio group, a lower alkylsulfonyl group or a substituted or unsubstituted sulfamoyl group;
B represents a hydroxyl group, a lower alkoxyl group or a hydroxyamino group;
G represents hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group or a lower alkyl group substituted with a heteroaryl group;
D represents OR7, NR7R8, NHNR7R8, NR7NHR8, SR7 or R7, wherein R7 and R8 may be the same or different from each other and each represents a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkenyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkenyl group substituted with an aryl group, a lower alkenyl group substituted with a heteroaryl group, a lower alkynyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkynyl group substituted with an aryl group, a lower alkynyl group substituted with a heteroaryl group, a halogeno-lower alkyl group, a halogeno-lower alkenyl group, a hydroxy-lower alkyl group, a hydroxy-lower alkenyl group or a substituted or unsubstituted amino-lower alkyl group, or R7 and R8 may be bonded together to form a ring which may contain one or two oxygen, nitrogen or sulfur atoms; and the substituent of the ring is a hydrogen atom, a halogen atom, hydroxyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkanoyl group, an aroyl group, a halogeno-lower alkanoyl group, a lower alkyloxy group, nitro group, cyano group, a substituted or unsubstituted amino group, carboxyl group, a lower alkoxycarbonyl group, a substituted or unsubstituted carbamoyl group, a lower alkylthio group, a lower alkylsulfonyl group or a substituted or unsubstituted sulfamoyl group; and
E and Exe2x80x2 may be the same or different from each other and each represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkyloxy group or nitro group.
The present invention provides an xcex14xcex27 integrin antagonist containing the above-described phenylalanine derivative or a pharmaceutically acceptable salt thereof as the active ingredient.
The present invention also provides a therapeutic agent or preventive agent and a pharmaceutical composition containing the phenylalanine derivative or a pharmaceutically acceptable salt thereof as the active ingredient, for diseases in which xcex14xcex27 integrin-depending adhesion process participates in the pathology, such as inflammatory intestinal diseases, diabetes, tumor proliferation and tumor metastasis.
The term xe2x80x9clowerxe2x80x9d in, for example, a lower alkyl group indicates that the group has 1 to 6 carbon atoms. Alkyl groups per se and also alkyl groups in alkenyl groups, alkynyl groups, alkoxyl groups, alkylthio groups, alkanoyl groups and alkylamino groups, alkenyl groups and alkynyl groups may be either linear or branched. Examples of these alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, secondary butyl group, tertiary butyl group, pentyl group and hexyl group. The alkenyl groups are, for example, vinyl group, propenyl group, butenyl group and pentenyl group. The alkynyl groups include ethynyl group, propynyl group, butynyl group, etc. The cycloalkyl groups include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, norbornyl group, adamantyl group, cyclohexenyl group, etc. The alkoxyl groups include methoxyl group, ethoxyl group, propyloxy group, isopropyloxy group, etc. The hetero atoms include nitrogen atom, oxygen atom, sulfur atom, etc. The halogen atoms are fluorine atom, chlorine atom, bromine atom and iodine atom. The halogenoalkyl groups include chloromethyl group, trichloromethyl group, trifluoromethyl group, trifluoroethyl group, pentafluoroethyl group, etc. The halogenoalkoxyl groups include trichloromethoxyl group, trifluoromethoxyl group, etc. The hydroxyalkyl groups include hydroxymethyl group, hydroxyethyl group, etc. The cycloalkyl groups which may contain a hetero atom(s) in the ring thereof include piperidyl group, piperazinyl group, morpholinyl group, pyrrolidinyl group, tetrahydrofuranyl group, etc. They also include piperidino group and morpholino group.
In the present specification, the aryl groups are both substituted and unsubstituted aryl groups such as phenyl group, 1-naphthyl group and 2-naphthyl group. They are preferably phenyl group and substituted phenyl group, and the substituents are particularly preferably halogen atoms, alkoxyl groups, alkyl groups, hydroxyl group, halogenoalkyl groups and halogenoalkoxyl groups. The heteroaryl groups are both substituted and unsubstituted heteroaryl groups such as pyridyl group, pyrimidinyl group, furyl group, thienyl group, indolyl group, quinolyl group, isoquinolyl group and 1,2,3-thiadiazolyl group. Preferred heteroaryl groups are pyridyl group, pyrimidinyl group, furyl group, thienyl group and 1,2,3-thiadiazolyl group and substituted pyridyl, pyrimidinyl, furyl, thienyl and 1,2,3-thiadiazolyl groups. Particularly preferred substituents are halogen atoms, alkoxyl groups, alkyl groups, hydroxyl group, halogenoalkyl groups and halogenoalkoxyl groups. The lower alkyl groups substituted with an aryl group include, for example, benzyl group and substituted benzyl groups. Particularly preferred substituents are halogen atoms, alkoxyl groups, alkyl groups, hydroxyl group, halogenoalkyl groups and halogenoalkoxyl groups. The lower alkyl groups substituted with a heteroaryl group include, for example, pyridylmethyl group, and particularly preferred substituents thereof are halogen atoms, alkoxyl groups, alkyl groups, hydroxyl group, halogenoalkyl groups and halogenoalkoxyl groups. The alkanoyl groups include, for example, formyl groups, acetyl groups, propanoyl group, butanoyl group and pivaloyl group. The aroyl groups include, for example, substituted or unsubstituted benzoyl group and pyridylcarbonyl group, and the substituents thereof are particularly preferably halogen atoms, alkoxyl groups, alkyl groups, hydroxyl group, halogenoalkyl groups and halogenoalkoxyl groups. The halogenoalkanoyl groups include, for example, trichloroacetyl group and trifluoroacetyl group. The alkylsulfonyl groups include, for example, methanesulfonyl group, ethanesulfonyl group, etc. The arylsulfonyl groups include, for example, benzenesulfonyl group and p-toluenesulfonyl group. The heteroarylsulfonyl groups include, for example, pyridylsulfonyl group. The halogenoalkylsulfonyl groups include, for example, trifluoromethanesulfonyl group. The alkyloxycarbonyl groups include, for example, methoxycarbonyl group, ethoxycarbonyl group and tertiary butoxycarbonyl group. The aryl-substituted alkoxycarbonyl groups include, for example, benzyloxycarbonyl group and 9-fluorenylmethoxycarbonyl group. The substituted carbamoyl groups include, for example, methylcarbamoyl group, phenylcarbamoyl group and substituted phenylcarbamoyl group, and the substituents thereof are particularly preferably halogen atoms, alkoxyl groups, alkyl groups, hydroxyl group, halogenoalkyl groups and halogenoalkoxyl groups. The substituted thiocarbamoyl groups include, for example, methylthiocarbamoyl group, phenylthiocarbamoyl group and substituted phenylthiocarbamoyl groups, and the substituents thereof are particularly preferably halogens, alkoxyl groups, alkyl groups, hydroxyl group, halogenoalkyl groups and halogenoalkoxyl groups. The substituents in the substituted amino groups herein include lower alkyl groups, lower alkyl groups substituted with an aryl group, lower alkyl groups substituted with a heteroaryl group, lower alkanoyl groups, aroyl groups, halogeno-lower alkanoyl groups, lower alkylsulfonyl groups, arylsulfonyl groups, heteroarylsulfonyl groups, halogenoalkylsulfonyl groups, lower alkyloxycarbonyl groups, aryl-substituted lower alkyloxycarbonyl groups, substituted or unsubstituted carbamoyl groups and substituted or unsubstituted thiocarbamoyl groups.
The group represented by X in the above general formula (1) is preferably an interatomic bond, xe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94SO2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94C(xe2x95x90O)xe2x80x94 or xe2x80x94NR1xe2x80x94SO2xe2x80x94. The group represented by X is particularly preferably xe2x80x94Oxe2x80x94, xe2x80x94NR1xe2x80x94C(xe2x95x90O)xe2x80x94 or an interatomic bond.
The group represented by Y is preferably CH.
The group represented by Z is preferably xe2x80x94C(xe2x95x90O)xe2x80x94 or xe2x80x94SO2xe2x80x94.
In the groups represented by A, the cycloalkyl groups which may contain a hetero atom(s) in the ring thereof, aryl groups and heteroaryl groups are either substituted or unsubstituted. The substituents thereof are those described above with reference to R2 to R6. The groups represented by A are preferably lower alkyl groups substituted with a group of general formula (2), groups of general formula (2) and heteroaryl groups.
The group represented by B is preferably a hydroxyl group or a lower alkoxyl group. It is particularly preferably a hydroxyl group.
The group represented by C is preferably a hydrogen atom.
In the groups represented by R7 or R8 among those represented by D, the cycloalkyl groups which may contain a hetero atom(s) in the ring thereof, aryl groups and heteroaryl groups are either substituted or unsubstituted, and the substituents are those described above with reference to R2 to R6. Examples of the groups, formed when D represents a group of the formula: NR7R8 wherein R7 and R8 together form a ring structure, include 1-piperidyl group, piperazine-1-yl group, morpholine-4-yl group and pyrrolidine-1-yl group.
As the groups represented by D, those represented by OR7, NR7R8, NHNR7R8, NR7NHR8 or SR7 are preferred. NR7R8, NHNR7R8, NR7NHR8 or SR7 is more preferred. NR7R8 or NHNR7R8 is particularly preferred. R7 and R8, which may be the same or different from each other, are each preferably a hydrogen atom, a lower alkyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, or a lower alkyl group substituted with a heteroaryl group. It is also preferred that R7 and R8 are bonded to each other to form a ring which may contain 1 or 2 oxygen atoms, nitrogen atoms or sulfur atoms. The substituents of the ring are preferably a hydrogen atom, halogen atoms, hydroxyl group, lower alkyl groups, aryl groups, heteroaryl groups, lower alkyl groups substituted with an aryl group, lower alkanoyl groups, aroyl groups, lower alkyloxy groups, nitro group, cyano groups, substituted or unsubstituted amino groups, carboxyl group, lower alkoxycarbonyl groups, lower alkoxycarbonyl groups substituted with an aryl group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted thiocarbamoyl group, lower alkylthio groups, lower alkylsulfonyl groups and substituted or unsubstituted sulfamoyl group. The groups represented by D are preferably hydroxyl group, phenylhydrazino group, 4-bromophenylhydrazino group, 4-rethoxyphenylhydrazino group, 4-cyanophenylhydrazino group, 4-methylphenylhydrazino group, 4-trifluoromethoxyhydrazino group, 3-methoxyphenylhydrazino group, etc.
The group represented by E or Exe2x80x2 is preferably a hydrogen atom.
The groups represented by R2 to R6 are more preferably a hydrogen atom, halogen atoms, hydroxyl group, lower alkyl groups, lower alkoxyl groups, halogeno-lower alkyl groups and halogeno-lower alkoxyl groups.
It is preferred that in general formula (1) in the present invention, X represents an interatomic bond or a group of the formula: xe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94SO2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94C(xe2x95x90O)xe2x80x94 or xe2x80x94NR1xe2x80x94SO2xe2x80x94, Y represents a group of the formula: xe2x80x94CH, Z represents a group of the formula: xe2x80x94C(xe2x95x90O)xe2x80x94, A represents a group of general formula (2), a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with a group of general formula (2), a lower alkyl group substituted with an aryl group or a lower alkyl group substituted with a heteroaryl group, B represents a hydroxyl group or a lower alkoxyl group, and C represents a hydrogen atom or a lower alkyl group.
It is preferred that (i) in general formula (1), X represents a group of the formula: xe2x80x94Oxe2x80x94, Y represents a group of the formula: CH, Z represents a group of the formula: xe2x80x94C(xe2x95x90O)xe2x80x94, A represents a lower alkyl group substituted with a group of general formula (2), R2, R3, R4, R5 and R6 may be the same or different from one another, and each represents a hydrogen atom or a halogen atom, B represents hydroxyl group or a lower alkoxyl group, C represents a hydrogen atom, D represents OR7, NR7R8 or NHNR7R8, R7 and R8 may be the same or different from each other and each represents a hydrogen atom, a lower alkyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group or a lower alkyl group substituted with a heteroaryl group, or R7 and R8 may be bonded together to form a ring which may contain one or two oxygen, nitrogen or sulfur atoms; and the substituents of the ring include a hydrogen atom, a halogen atom, hydroxyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, an aryl group, a heteroaryl group, a lower alkyl group substituted with a cycloalkyl group which may contain a hetero atom(s) in the ring thereof, a lower alkyl group substituted with an aryl group, a lower alkyl group substituted with a heteroaryl group, a lower alkanoyl group, an aroyl group, a halogeno-lower alkanoyl group, a lower alkyloxy group, nitro group, cyano group, a substituted or unsubstituted amino group, carboxyl group, a lower alkyloxycarbonyl group, a substituted or unsubstituted carbamoyl group, a lower alkylthio group, a lower alkylsulfonyl group or a substituted or unsubstituted sulfamoyl group, and E and Exe2x80x2 each represents a hydrogen atom.
It is preferred that in above condition (i), X represents a group of the formula: xe2x80x94NR1xe2x80x94C(xe2x95x90O)xe2x80x94, Y represents a group of the formula: CH, Z represents a group of the formula: xe2x80x94C(xe2x95x90O)xe2x80x94 and A represents a heteroaryl group. It is also preferred that X represents an interatomic bond, Y represents a group of the formula: CH, Z represents a group of the formula: xe2x80x94C(xe2x95x90O)xe2x80x94 and A represents a group of general formula (2).
The following compounds and pharmaceutically acceptable salts thereof are preferred:
N-(trans-4-carboxycyclohexane-1-carbonyl)-O-(2,6-dichlorobenzyl)-L-tyrosine;
N-(trans-4-phenylhydrazinocarbonylcyclohexane-1-carbonyl)-O-(2,6-dichlorobenzyl)-L-tyrosine; and
N-[trans-4-(4-bromophenylhydrazinocarbonyl)cyclohexane-1-carbonyl]-O-(2,6-dichlorobenzyl)-L-tyrosine.
The following compounds and pharmaceutically acceptable salts thereof are preferred: 
The phenylalanine derivatives (1) of the present invention can be synthesized by methods described below. For example, a phenylalanine derivative (8) of general formula (1) wherein xe2x80x94Xxe2x80x94A represents a group defined by Q described below, Y represents a group of the formula: CH, Z represents a group of the formula: xe2x80x94C(xe2x95x90O)xe2x80x94, B represents hydroxyl group and C represents a hydrogen atom can be synthesized as shown below. A symbol xe2x80x9cxe2x97xafxe2x80x9d in schemes 5 and 6 represents a resin such as Wang resin. 
A suitably protected carboxylic acid (3) is attached to a resin by a usual method. The substituent Q of the carboxylic acid (3) has a structure of xe2x80x94Xxe2x80x94A as described above with reference to the general formula (1), it is a substituent convertible into xe2x80x94Xxe2x80x94A in any stage of the synthesis or it has a suitably protected structure. As for the attachment reaction conditions, the reaction can be conducted by using, if necessary, a suitable additive such as HOAt (1-hydroxy-7-azabenzotriazole) or HOBt (1-hydroxybenzotriazole) and a condensing agent such as DIC (diisopropylcarbodiimide), DCC (dicyclohexylcarbodiimide) or EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) in an organic solvent such as dichlorornethane, DMF (N,N-dimethylformamide) or NMP (N-methyl-2-pyrrolidone). For example, when Wang resin is used, the reaction is carried out in the presence of pyridine and 2,6-dichlorobenzoyl chloride in DMF to obtain an ester (4). A protective group P1 is removed from the ester (4) under suitable conditions to obtain an amine (5). For example, when Fmoc group (9-fluorenylmethoxycarbonyl group) is used as P1, the protective group can be removed with a base such as piperidine in a solvent such as DMF. The amine (5) can be converted into a carboxylic acid (6) by condensing it with 1,4-cyclohexanedicarboxylic acid (11) by using a condensing agent such as DIC and, if necessary, a suitable additive such as HOAt or HOBt in an organic solvent such as DMF, NMP or dichloromethane. The carboxylic acid (6) can be converted into a carbonyl derivative (7) by reacting it with an amine, an alcohol, a hydrazine or a thiol under the same conditions as those in the above-described condensation reaction. 
The amine (5) can be converted into a carbonyl derivative (7) by reacting it with a carboxylic acid (12), synthesized by a method described later, under the above-described condensation reaction conditions. 
The carbonyl derivative (7) obtained as described above is cleaved from the resin under suitable conditions to obtain it in the form of a carboxylic acid (8). For example, when Wang resin is used as the resin, the product is treated with an acid reaction solution containing, for example, TFA (trifluoroacetic acid) to obtain a carboxylic acid (8) solution and then the solvent is evaporated to obtain a carboxylic acid (8). The carboxylic acid (8) thus obtained is purified by the column chromatography, HPLC, recrystallization or the like to obtain the pure carboxylic acid (8).
The compounds of the general formula (1) can be synthesized also by the following method: 
A suitably protected amine (9) is reacted with 1,4-cyclohexanedicarboxylic acid or a carboxylic acid (12), synthesized by a method described later, by using, if necessary, a suitable additive such as HOAt or HOBt and a condensing agent such as DIC, DCC or EDC in an organic solvent such as dichloromethane, DMF or NMP to obtain a carbonyl derivative (10). The substituent Q of the amine (9) has a structure of xe2x80x94Xxe2x80x94A as described above with reference to the general formula (1), or it is a substituent convertible into xe2x80x94Xxe2x80x94A in any stage of the synthesis ,or the substituent is suitably protected. The protective group is removed from thus obtained carbonyl derivative (10) under suitable reaction conditions to obtain the carboxylic acid (8). For example, the protective group can be removed by the alkali hydrolysis when P2 is methyl or ethyl group, or by the treatment with an acidic solution when P2 is t-butyl group or by the hydrolysis or by the reaction with hydrogen in the presence of a metal catalyst when P2 is benzyl group or the like. When 1,4-cyclohexanedicarboxylic acid (11) is used as the starting carboxylic acid, a carboxylic acid (8) is obtained via a carbonyl derivative (10) of the above formula wherein D represents hydroxyl group.
The carboxylic acid (12) can be synthesized by the following method: 
Namely, 1,4-cyclohexanedicarboxylic acid (11) is reacted with a suitable amount of an amine, an alcohol, a hydrazine or a thiol by using a suitable condensing agent such as DIC, DCC or EDC in the presence of a suitable additive in a suitable organic solvent such as dichloromethane or DMF and then the product is purified by a suitable method such as column chromatography or recrystallization to obtain the carboxylic acid (12). 
A monocarboxylic acid (14) can be obtained by esterifying 1,4-cyclohexanedicarboxylic acid (11) by an ordinary method to form a diester (13) and then reacting the diester (13) with a suitable amount of a base such as sodium hydroxide, potassium hydroxide or lithium hydroxide in an organic solvent such as methanol, ethanol or THF or in a mixture of the organic solvent with water. The inonocarboxylic acid (14) is reacted with a suitable amount of an amine, an alcohol, a hydrazine or a thiol by using a suitable condensing agent such as DIC, DCC or EDC in the presence of a suitable additive in a suitable solvent such as dichloromethane or DMF to obtain a carbonyl derivative (15) and then this product is hydrolyzed under the same reaction conditions as those described above to obtain the carboxylic acid (12).
Various partial structures represented by xe2x80x94Xxe2x80x94A in the general formula (1) can be synthesized from corresponding precursors by reactions described below. By the reactions described below, Q in the precursor structure can be converted into xe2x80x94Xxe2x80x94A in a suitable stage in the steps in schemes 5 to 8 which are ordinary methods for synthesizing the compounds of the general formula (1).
When Q is hydroxyl group or a suitably protected hydroxyl group, the protective group is removed, if necessary, to form hydroxyl group and then the subsequent conversion reaction can be conducted as described below.
Hydroxyl group Q can be reacted with an alkylating agent such as an alkyl halide or an alkyl sulfonate in the presence of a suitable base in an organic solvent to form various ether-type structures. The ether-type compounds can be formed also by subjecting the obtained compound to Mitsunobu reaction with an alcohol in the presence of a dialkylazodicarboxylic acid. The compounds having structures of various aryl ether types or heteroaryl ether types can be formed by reacting the obtained compound with an aryl halide or a heteroaryl halide in the presence of a suitable base or catalyst in an organic solvent.
Hydroxyl group Q can be reacted with a sulfonic acid halide or sulfonic acid anhydride in the presence of an organic base such as triethylamine, dilsopropylethylamine, pyridine or N,N-dimethylaminopyridine or an inorganic base such as potassium carbonate or sodium carbonate in an organic solvent such as DMF or dichloromethane to form a corresponding product having a sulfonic acid ester type structure.
A trifluoromethanesulfonic acid ester (hereinafter referred to as xe2x80x9ctriflatexe2x80x9d can be obtained under the above-described sulfonation reaction conditions. The triflate can be converted into an aryl-substituted compound or a heteroaryl-substituted compound by Suzuki coupling reaction wherein it is reacted with a boric acid compound in the presence of a palladium catalyst such as tetrakistriphenylphosphine palladium or palladium acetate or another metal catalyst in a solvent such as DMF, DME (1,2-dimethoxyethane), toluene or dioxane at room temperature or under heating. The conversion reaction into the aryl-substituted compounds can be carried out by using not only the triflate but also a compound of the above formula wherein Q is substituted with a halogen atom.
When Q is a properly protected amino group, the protective group can be removed to form the amino group by a method suitably selected depending on the protective group. When Q is nitro group, it can be converted into the amino group by the hydrogenation reaction in the presence of a metal catalyst or by the reduction reaction with a reducing agent selected from the group consisting of various reducing agents. The amino group thus obtained can be further converted into groups of various structures by various reactions described below.
The amino group can be further converted into an alkylamino group by reacting it with an alkylating agent such as an alkyl halide or an alkyl sulfonate in the presence of a suitable base in an organic solvent. Various arylamine structures can be formed by reacting the amino group with an aryl halide in the presence of a suitable base in an organic solvent.
The amino group can be converted into an alkylamino group by reacting it with an aldehyde or a ketone in the presence of a reducing agent such as sodium borohydride or sodium cyanoborohydride in a solvent such as DMF, dichloromethane, a trialkylorthoformic acid or a trialkylorthoacetic acid. The amino group or alkylamino group can be converted into groups of various structures by reactions described below.
The amino group or alkylamino group can be converted into a corresponding structure of amide type or sulfonamide type by reacting it with a carboxylic acid halide, a carboxylic acid anhydride, a sulfonic acid halide or a sulfonic acid anhydride in the presence of an organic base such as triethylamine, diisopropylethylamine, pyridine or N,N-dimethylaminopyridine or an inorganic base such as potassium carbonate or sodium carbonate in an organic solvent such as DMF or dichloromethane. The amino group or alkylamino group can be converted into a corresponding structure of amide type also by reacting it with a carboxylic acid in the presence of a suitable additive and condensing agent in an organic solvent such as DMF or dichloromethane.
The amino group or alkylamino group can be converted into a corresponding structure of urea type or thiourea type by reacting it with an isocyanate or an isothiocyanate in the presence of, if necessary, an organic base such as triethylamine, diusopropylethylamine, pyridine or N,N-dimethylaminopyridine in an organic solvent such as DMF, toluene or dichloromethane.
The product having the sulfonamide structure formed as described above can be alkylated by the above-described Mitsunobu reaction with an alcohol. The alkylation reaction can be carried out also by reacting the compound with an alkylating agent such as an alkyl halide or an alkyl sulfonate in the presence of a suitable base in an organic solvent.
It is possible that the phenylalanine derivatives represented by the general formula (1) in the present invention have optical isomers because they have an asymmetric carbon atom. The compounds of the present invention also include those optical isomers. Various tautomers of the phenylalanine derivatives of the general formula (1) are possible in the present invention because they contain movable hydrogen atoms. The compounds of the present invention also include those tautomers.
When the compounds of general formula (1) can form salts thereof, the salts are pharmaceutically acceptable ones. When the compound has an acidic group such as carboxyl group, the salts can be ammonium salts, or salts thereof with alkali metals, e.g. sodium and potassium, salts thereof with alkaline earth metals, e.g. calcium and magnesium, salts thereof with aluminum and zinc, salts thereof with organic amines, e.g. triethylamine, ethanolamine, morpholine, piperidine and dicyclohexylamine, and salts thereof with basic amino acids, e.g. arginine and lysine. When the compound has a basic group, the salts can be those with inorganic acids, e.g. hydrochloric acid, sulfuric acid and phosphoric acid; those with organic acids, e.g. acetic acid, citric acid, benizoic acid, maleic acid, fumaric acid, tartaric acid and succinic acid; and those with organosulfonic acids, e.g. methanesulfonic acid and p-toluenesulfonic acid. The salts can be formed by mixing a compound of the general formula (1) with a necessitated acid or base in a proper ratio in a solvent or dispersing agent or by the cation exchange or anion exchange reaction with another salt.
The compounds of the general formula (1) of the present invention also include solvates thereof such as hydrates and alcohol adducts thereof.
The compounds of general formula (1) and salts thereof are administered as they are or in the form of various medicinal compositions to patients. The dosage forms of the medicinal compositions are, for example, tablets, powders, pills, granules, capsules, suppositories, solutions, sugar-coated tablets, depots and syrups. They can be prepared with ordinary preparation assistants by an ordinary method.
For example, the tablets are prepared by mixing the phenylalanine derivative, the active ingredient of the present invention, with any of known adjuvants such as inert diluents, e.g. lactose, calcium carbonate and calcium phosphate; binders, e.g. acacia, corn starch and gelatin; extending agents, e.g. alginic acid, corn starch and pre-gelatinized starch; sweetening agents, e.g. sucrose, lactose and saccharin; corrigents, e.g. peppermint, Akamono (Gaultheria aderothrix) oil and cherry; lubricants, e.g. magnesium stearate, talc and carboxymethyl cellulose; excipients for soft gelatin capsules and suppositories, e.g. fats, waxes, semi-solid or liquid polyols, natural oils and hardened oils; and excipients for solutions, e.g. water, alcohols, glycerols, polyols, sucrose, inverted sugars, glucose and vegetable oils.
The antagonist containing one of the compounds of above general formula (1) or one of salts thereof as active ingredient is usable as a therapeutic agent or preventing agent for diseases in which xcex14xcex27 integrin-depending adhesion process participates in the pathology, such as inflammatory bowel diseases, diabetes, tumor proliferation and tumor metastasis.
The dose of the compound of general formula (1) or salt thereof used for the above-described purpose varies depending on the intended therapeutic effect, administration method, period of the treatment, and age and body weight of the patient. The dose is usually 1 xcexcg to 5 g a day for adults in the oral administration, and 0.01 xcexcg to 1 g a day for adults in the parenteral administration.